An Angel Business Communications publication October 2010 Volume 16 Number 7
Outsourced growth
The increasing trend of outsourcing
expertise
Femto boost4G communications will benefit
Gate scalingFraunhofer IAF targetsterahertz circuits
Opening to industryRFMD invites industry tomake use of its MBEexpertise and tools
CS EuropeGuiding the futuredirection of the industry
Foundry for allEuropean foundrybacked for photonicintegrated circuits
Research ReviewSimplifying GaN VCSEL fabrication
NewsRecord breaking III-V’sIndustry leader retiresGaAs demand to riseTSMC enters solar
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October 2010Volume 16 Number 7
CONNECTING THE COMPOUND SEMICONDUCTOR COMMUNITY
Shifting landscapes
The phrase “real men have fabs” summed up the feeling within the silicon
industry a decade or so ago. But times have changed. Capital
expenditure costs have soared as node sizes have come down,
and today, aside from a very small number of
heavyweights, silicon chipmakers now outsource
production.
Within the III-V industry, it seems that some sectors
are taking a slow stroll down a similar path. While LED
manufacture, certainly by the biggest players, is still very
much an in-house affair, the trend amongst the producers of
GaAs chips for wireless applications is to outsource some
production.
This transition started several years ago, with contracts such as the
epiwafer supply agreement between Skyworks and Kopin. But it has been gathering pace, thanks
to moves such as Anadigics’ pursuit of a hybrid manufacturing model. IQE is used as a source for
epiwafers, and some of the company’s chip production is handled by WIN Semiconductors.
Activities such as this are helping to swell IQE’s revenue, which is increasingly dominated by sales
of wireless products. But the continued success of this global epiwafer supplier may depend on
whether it loses market share to a new player in the wireless epiwafer business: RFMD. Yes, that’s
right, the world’s biggest in-house manufacturer of GaAs RF chips is opening the doors of its MBE
facility.
RFMD’s motivations for entering the epiwafer supplier market are entirely predictable. It’s keen to
open up a new revenue stream and net a good return on its substantial investment in capital
equipment.
The company is certainly well equipped for its new venture. It can offer customers a selection of
multi-wafer 6-inch MBE kits equipped with the latest in-situ monitoring tools, plus a strong portfolio
of metrology tools for characterizing these epiwafers. This includes a multi-field Hall probe for non-
destructive measurements of mobility and carrier concentration in multiple layers.
Armed with these attributes, RFMD should enjoy some success as an epiwafer supplier.
What will be interesting to see is if this offering leads to further outsourcing of epiwafer growth, and
whether it spurs the trend amongst GaAs chip makers to move away from vertical integration.
Richard Stevenson PhD
Consultant Editor
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October 2010 www.compoundsemiconductor.net 5
Volume 16 Number 7
CONNECTING THE COMPOUND SEMICONDUCTOR COMMUNITY contents
17 Amping communications
The emergence of 4G smartphones is placing a
tremendous strain on mobile carriers. But this can be
relieved by adding femtocells to the network that are
built around customized power amplifiers.
21 Gate reductions
Gate scaling is the key to penetrating the depths of
the sub-millimeter-wave frequency range. It improves
RF performance, empowering active electronics at
these ultra-high frequencies.
27 Welcoming opportunity
Diversification: that’s the central pillar of RF Micro
Devices’ growth strategy. To continue to execute on
that front it is opening up its MBE facility and starting
to offer various services that include shipments of
arsenic- and phosphorous-based epiwafers.
30 CS Europe
Europe’s premier Compound Semiconductor
conference is approaching and the question being
asked is what next for the future of the Compound
Semiconductor in a changing market place
32 Photonics fab for all
High costs are impairing the chances of success for
small companies pioneering novel devices based on
photonic ICs. Europe is funding the creation of an InP
foundry that will use generic processes to create
devices for multiple applications
37 Research Review
Simplifying GaN VCSEL
Combatting the droop
industry & technology
news
17
2723
07
11 12
10
06 Record breaking III-V’s
GaAs growth continues
08 Industry leader retires
GaAs growth continues
10 New fabrication
Meeting new growth
11 Mid infra red laser growth
Highest order book
12 Deep UV LED collaboration
Low defect AlGaN substrates
14 Laser shipment exceeded
GaN for blue LED
6 www.compoundsemiconductor.net October 2010
news � review
IEDM to showcase record-breaking III-Vs
contact resistance and capacitance
parasitics. The 1.7S/mm transconductance
at 1THz (fmax) was achieved at 0.75V input
voltage.
The meeting will also detail the efforts of a
team led by University of Tokyo that has
fabricated the world’s first InGaAs MOSFET
built on an insulating substrate, and also the
thinnest InGaAs MOSFET ever made, with a
tiny 3.5nm channel. Nonconducting
substrates are key to the eventual
integration of such devices with silicon
CMOS architectures because they reduce
short-channel effects. This device has dual
gates and demonstrated good on/off
characteristics (~107) and
transconductance. The team direct wafer-
bonded their transistor to silicon. They
avoided creating unwanted source-drain
junctions, which, because of the extremely
thin films that make up the device, would
have been difficult to anneal and would have
made ion implantation difficult. Instead, they
substituted an n-doped accumulation-mode
channel.
Meanwhile, a partnership between Intel and
IQE will report the development of a InGaAs
FinFET for low-power logic. FinFETs are
nanoscale transistors with long, thin
channels surrounded by multiple gates that
provide superior on/off control versus planar
devices. InGaAs, meanwhile, is a compound
semiconductor that yields faster, more
energy-efficient transistors than silicon.
FinFETs made from InGaAs may make
possible ultra-dense yet low-power logic
circuits. The first surface-channel InGaAs
FinFET was described at the 2009 IEDM,
but this year a team led by Intel will discuss
InGaAs quantum-well FinFETs with
enhanced overall electrical performance,
including good control of troublesome short-
channel effects. The performance was made
possible by 35nm-wide and smaller fins;
ultra-small 5nm gate-to-drain and gate-to-
source separations; a high-k gate dielectric,
and a simplified source/drain architecture.
THIS YEAR’S IEEE Electron Devices
Meeting (IEDM) will include coverage of a
400 GHz GaN HEMT, an InGaAs terahertz
transistor, an InGaAs FinFET for low-power
logic and the world’s first InGaAs MOSFET
on an insulating substrate.
At IEDM 2010, which will be held in San
Francisco from 6-8 December, a team from
HRL will be claiming the speed record for a
GaN HEMT. The GaN-on-SiC transistor
produced by this US defence giant has a
40 nm gate and produces a cut-off
frequency of 220 GHz and a maximum
oscillation frequency of 440 GHz.
According to HRL, one of the challenges
associated with making a transistor out of
GaN is the realization of a good electrical
contact with the material, given its high
resistance. The team overcame this by re-
growing the ohmic contacts using
molecular-beam epitaxy. Ultra-high speed
transistors will be reported by a team led by
Teledyne Scientific. This effort has led to a
1-THz InGaAs Transistor with “good” gain.
This team’s transistor is a 50nm gate-length
enhancement-mode PHEMT that was built
on InP and has good transconductance
(1.7S/mm) at moderate voltage levels. Key
to its performance are the short gate length
and a small channel (10nm thick), which
maximize carrier transport and minimize
TSMC Begins Building first Thin Film Solar R&D Centre and Fab
TAIWAN SEMICONDUCTOR
MANUFACTURING COMPANY, LTD broke
ground in Taichung’s Central Taiwan
Science Park on the company’s first Thin
Film Solar R&D Centre and Fab, laying the
foundation for the company’s entry into the
thin-film solar photovoltaic (PV) market.
“TSMC’s New Businesses team has
reached many important milestones since it
was formed last year, first with our LED
facility in Hsinchu, and now with
construction in Taichung on our first solar
facility. Our solar and LED businesses will
not only bolster TSMC’s revenue and profit
growth in the coming decades, they also
play a key role in TSMC’s corporate social
responsibility by making products that
support a greener earth.“ said TSMC
Chairman and CEO Dr. Morris Chang. “In
addition, construction of this solar R&D
centre and fab, along with our Fab 15
Gigafab next to it, means Taichung’s Central
Taiwan Science Park will become home to
much of TSMC’s most advanced and
innovative production.”
“TSMC has always been committed to
technology leadership, and our solar
business will be no different,” said Dr. Rick
Tsai, TSMC President of New Businesses.
“The research performed at this R&D centre
will help us achieve our goal of offering a
leading thin-film solution and the production
at this fab, drawing on TSMC’s wealth of
manufacturing know-how, will pave the way
for us to become a top provider of solar PV
modules.”
TSMC plans to invest US$258 million for
the first phase of the Thin Film Solar R&D
Centre and Fab, which is scheduled for
equipment move-in in the second quarter of
2011 and achieve initial volume production
of 200MW (megawatts) per year in thin-film
photovoltaic modules in 2012.
TSMC also plans to add a second phase to
the facility and expand production to more
than 700MW, employing about 2,000 total
staff in the facility.
In addition, the R&D centre in the facility
will continue to develop the CIGS
technology licensed from Stion in June
of this year. TSMC will offer its solar
products around the world under its own
brand.
October 2010 www.compoundsemiconductor.net 7
review � news
Epistar and Toyoda enter An LED
cross license agreementEPISTAR CORPORATION and Toyoda
Gosei have entered a cross license
agreement to allow the companies
(including subsidiaries)to use each other’s
patents for specific technologies in Group
III-V compound semiconductor light emitting
diodes (“LEDs”), which include InGaN LEDs
and AlGaInP LEDs.
Epistar is the only company in Taiwan,
getting the cross license from Toyoda Gosei
and no any other company in Taiwan gets
any cross license from Toyoda Gosei .
Epistar holds valuable patents for high-
brightness AlGaInP LEDs and high-power
GaN LEDs. Toyoda Gosei likewise holds a
number of valuable patents for InGaN LEDs.
Epistar and Toyoda Gosei agreed to
construct an environment wherein they will
respect and mutually utilize each other’s
technologies in order to further advance the
market for LED products.
This agreement will allow both Epistar and
Toyoda Gosei significantly more freedom in
their development efforts by eliminating the
need for concern about each other’s
patents. By facilitating research at both
companies, new developments in LED
technology are anticipated, including an
acceleration of research to improve the
luminosity of LEDs. Epistar and Toyoda
Gosei each intend to maintain a friendly
business relationship and pursue the
development of superior high-luminosity
LEDs and further expansion of the LED
market through fair competition.
IQE’s Singapore operation recognized as
a top supplier to TriQuintIQE, a supplier of advanced semiconductor
epitaxial wafer products and wafer services
to the semiconductor industry, announces
that IQE’s Singapore operation, MBE
Technology Pte Ltd, has been recognized as
a top supplier to leading wireless chip
manufacturer, TriQuint Semiconductor, Inc.
TriQuint, a leading RF front-end product
manufacturer and foundry services provider,
announced its Top Supplier Awards for
2009 during TriQuint’s Supplier Day
Conference, an annual educational and
networking event for TriQuint’s top suppliers
held in Portland, Oregon.
Winners were selected by members of
TriQuint’s Supply Chain and Business Unit
organizations in recognition of TriQuint’s top
suppliers for their overall performance to
TriQuint including innovation, operational
excellence, service levels, and industry
leadership.
Steve Grant, Vice President of Worldwide
Operations said: “The capability of our
strategic suppliers to provide us with zero-
defect material, position capacity to support
TriQuint’s continued growth, and collaborate
on reducing costs while developing
innovative solutions greatly contributes to
our ability to deliver RF solutions that
improve the performance and lower the cost
of our customers’ applications.”
Receiving the award, together with Dr J
Jiang Sales Director of MBET, Dr. Drew
Nelson, IQE Group CEO and President
said: “We are delighted that MBE
Technology has been honoured with this
award from one of the leading chip
manufacturers in the wireless industry. IQE
enjoys a close working relationship with
many of its customers globally and the
particular recognition of our Singapore
operation by TriQuint demonstrates the
Group’s commitment to providing the
highest level of quality in terms of products,
services and innovation.
8 www.compoundsemiconductor.net October 2010
news � review
Aldo Kamper succeeds Dr.
Rüdiger Müller as President
and CEO of OSRAM
AS of October 1, 2010, Aldo
Kamper (40), a proven LED
expert and time-tested
executive, is succeeding Dr.
Rüdiger Müller (65) who, after
heading optoelectronic
semiconductor business for 22
years at OSRAM and formerly
at Siemens, is bidding farewell
on reaching retirement age.
Martin Goetzeler, CEO of the parent
company OSRAM said: “Down to this very
day, Dr. Rüdiger Müller has been one of the
driving forces worldwide in the development
of LED technology, which now reaches far
into our everyday lives. With Aldo Kamper
we have been able to win a successor from
our own ranks – someone who will advance
OSRAM Opto Semiconductors and make
his own mark.”
Dr. Müller hands over the reins of OSRAM
Opto Semiconductors to Aldo Kamper on
October 1, 2010. Kamper started his
professional career at OSRAM in 1994 after
completing his business administration
studies. Since 2006, he has held the post
The GaAs market staged a strong
recovery toward the end of a tumultuous
2009 as a result of positive trends in
wireless markets. The Strategy Analytics
GaAs and Compound Semiconductor
Technologies (GaAs) service report,
“GaAs Industry Forecast 2009-2014,”
calculates that despite a recession,
GaAs industry revenues managed to
escape a drop in 2009, with a strong
performance in the second half of the
year translating to year-on-year revenues
remaining flat at $3.7 billion.
GaAs technology will maintain its
position as the enabling technology for
next generation cellular handsets. The
smartphone category of the handset
market, in particular, provided a vital
lifeline in 2009, boasting stronger than
average annual growth in terminal
volumes.
With an increasing average number of
GaAs power amplifiers per terminal as
well as increasing switch complexity in
this sector, GaAs device demand from
next generation handsets will grow faster
than overall industry revenue growth.
“Our analysis incorporates individual
wireless, consumer, infrastructure and
defence market forecasts—taking into
account technology trends,” noted Asif
Anwar at Strategy Analytics. “There is no
question that the improving capabilities
of silicon and silicon germanium
technologies, as well as emerging
technologies such as gallium nitride, will
provide increasing competition for GaAs
technologies.”
“Despite this competition, GaAs device
demand will continue to see continued
growth through 2014. The market will
grow at a compound annual growth rate
of 5% to be worth over $4.7 billion,”
concluded Anwar.
of Executive Vice President &
General Manager Specialty
Lighting at OSRAM Sylvania
in the US.
Dr. Rüdiger Müller’s retirement
brings an era to an end at
OSRAM Opto
Semiconductors and in LED
technology. Müller headed the
optoelectronic semiconductor
business at Siemens from 1988 and, in
1999, was also founding CEO of OSRAM
Opto Semiconductors, in which Siemens’
LED and infrared business was pooled with
OSRAM’s lighting competence. Besides
strong growth and the continuous expansion
of production capacities his name is most
closely linked with technological advances
in optoelectronic semiconductor technology.
Crucial innovations, such as thin-film
technology, direct blue or green
semiconductor laser diodes, the first OLED
product or the first surface-mountable LED
(SMT-LED), innovations that set standards
to this very day, emerged under his
leadership.
GaAs devicedemand willcontinue to seecontinued growththrough 2014
Kopin Awarded $750,000 to DevelopAdvanced Nitride Electronic Materials
KOPIN CORPORATION has received a
two-year, Phase II Small Business Innovative
Research (SBIR) contract. The contract will
cover the development of Aluminum Indium
Nitride-based high electron mobility
transistors (AlInN HEMTs). The $750,000
award through the Missile Defense Agency
(MDA) will leverage Kopin’s established
capability in Group III-Nitrides to enhance
the performance and manufacturability of
AlInN materials.
“This SBIR program by MDA validates the
potential of the AlInN material system for
high-performance electronic devices,”
stated John C.C. Fan, Kopin’s President and
CEO. “Our long-term objective is to
commercialize AlInN-based electronic
materials, which parallels our highly
successful GaAs HBT wafer business.”
Wayne Johnson, Kopin’s Vice President of
Technology said, “The AlInN material system
has shown promise to extend the power and
frequency capability of GaN-based HEMTs.”
“During the Phase I effort, we demonstrated
results in AlInN/GaN heterostructures
including record-low sheet resistance. The
goals of Phase II will involve optimization of
the AlInN HEMT structures and fabrication
of HEMT devices for X-band electronics
applications in collaboration with leading-
edge GaN foundries,” concluded Johnson.
October 2010 www.compoundsemiconductor.net 9
review � news
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LayTec has successfully installed an
EpiCurveTT on an Aixtron Close Coupled
Showerhead (CCS) MOCVD system at
Fraunhofer Institute for Applied Solid State
Physics (IAF) in Freiburg, Germany. This is
the first time an EpiCurveTT has been
installed on a showerhead system on only
one viewport.
In the past, since the viewports of such
systems are so small, 2 separate windows
were used: one for curvature and one for
temperature and reflectance measurements.
Now, due to the improved design, all three
parameters are measured through one
standard AIX CCS viewport.
Chunyu Wang and his team at IAF will use
the tool for growth control of GaN on silicon
substrates. The simultaneous in-situ
monitoring of wafer temperature, reflectance
and curvature will be used to engineer the
stress in the epilayers. Wang commented,
“The new sensor will help us to get flat and
crack-free GaN layers on Si substrates for
future sophisticated electronic devices.”
Recently, LayTec launched EpiCurveTT AR
(advanced resolution) for measurements of
the aspherical curvature component during
epitaxial growth. The tool is claimed to be
the perfect solution for Planetary and other
gas-foil rotation MOCVD systems where the
azimuth of the rotating wafers is unknown.
The standard EpiCurveTT without AR
measures randomly either along the major
axis (larger bow - blue arrow in Fig. 2) or
along the minor axis (smaller bow - red
arrow in Fig. 2). In a Planetary reactor the
phase of rotation is unknown. As a result,
the signal looks “noisy” (red line in Fig. 3): it
oscillates between the maximum and the
minimum of the azimuthal aspherical bow.
The new tool measures curvature along two
perpendicular axes and eliminates 2nd order
azimuthal bowing effects. The signal-to-
noise ratio of the tool with advanced
resolution improves the curvature signal
from ±8 km-1 (red line) to ± 0.2 km-1 (black
line) and measures only the main curvature
component by eliminating the aspherical
contribution.
Laytec installs Single-port EpiCurveTT for
Aixtron showerhead
10 www.compoundsemiconductor.net October 2010
news � review
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Albemarle builds in South Korea To meet growthALBEMARLE CORPORATION have
announced that it has begun its largest
capital investment in the fast growing Asia
Pacific region of Yeosu, South Korea.
The Yeosu site contains existing R&D as
well as pilot plant equipment that will be
modified to enable customer qualification
efforts in 2010. The site will effectively mirror
Albemarle’s world scale metallocene
polyolefin catalyst and Trimethyl Gallium
(TMG) capabilities located in Baton Rouge,
Louisiana.
Albemarle will build on its leading supply
and technology position in metallocene
catalysts by leveraging its breakthrough
ActivCat(TM) technology for polyolefin
production. The company will also leverage
its 50+ years of production experience in
metal organics to supply High Purity Metal
Organics (HPMOs) such as TMG to the
High Brightness LED (HBLED) market.
Mark Rohr, Albemarle’s Chairman and Chief
Executive Officer, commented, “This
strategic investment signifies our
commitment to expand our footprint in
regions that provide substantial growth
opportunities for Albemarle and its
customers. By providing local manufacturing
and Albemarle’s renowned excellence in
technical service and support, we are giving
our customers a competitive advantage in a
growing market. We thank the governor of
Jeollanam-do province and the mayor of
Yeosu city for their support and advice as
we undertake this important project.”
The Yeosu site will be capable of producing
mPO catalyst lab samples followed by pilot
samples for qualification trials with local
customers this year. Intermediate
commercial operations will begin in mid-
2011, with the commercial facility being fully
operational in 2012. The site will produce
finished catalysts, activators like
methylaluminoxane (MAO) and
organoborons, as well as metallocene
components. The site will also purify metal
organics, creating a portfolio of HPMOs for
electronic applications. TMG production will
begin in early 2011, with other HPMOs
phased into the project throughout 2011.
‘’We are excited to announce the quick
startup of this new facility and look forward
to meeting our Asian customers’ current
needs through local supply in both the mPO
industry as well as the HBLED industry. The
premier location of this new manufacturing
site will give Albemarle a strong competitive
advantage in Asia Pacific and secures our
position as the global leader for metallocene
Polyolefins catalysts,” said Amy Motto,
Division Vice President, Polyolefin and
Chemical Catalysts.”
October 2010 www.compoundsemiconductor.net 11
review � news
Growth expected in
mid-infrared lasers, says
Strategies Unlimited
ADVANCEMENTS in several new laser
technologies are opening new opportunities
in the part of the spectrum between telecom
lasers and the nascent terahertz range,
called the mid-infrared.
This range is currently dominated by
applications in materials processing and
medical procedures, but new military and
sensing applications will add sizeable and
exciting opportunities in the next few years.
The new segments will grow 30% per year,
compounded annually through 2014. But,
the mid-IR range remains a complex and
confusing segment, with competition from
other laser and non-laser solutions, and with
many companies ripe for acquisition. These
are among the findings in a new report, Mid-
Infrared Lasers 2010, from Strategies
Unlimited, the leader in market research of
the photonics industry.
The mid-infrared is best known for being a
covert and eye-safe range, for the thermal
vibrations of molecules (used in sensing and
thermal imaging), and for the cheap photons
of high-power CO2 lasers. CO2 lasers
today dominate the sales, from 10 Watt
lasers using sealed gas tubes to multi-
kilowatt lasers using flowing gas blowers,
for use in materials processing. Solid-state
lasers are also established in medical
applications.
Next to come are high-brightness sources
for military applications: infrared
countermeasures against heat-seeking
missiles, illuminators for thermal imaging,
mid-IR beacons, and so forth. These military
applications are key to funding the new mid-
infrared technologies while other
applications get off the ground.
Another long-awaited segment is sensing
for molecular detection, with many exciting
new opportunities in environmental
monitoring, industrial process controls,
security standoff detection of hazardous
chemicals, and new breathalyzer
instruments for medical diagnostics.
Other sensor applications include mid-
infrared rangefinding and Doppler
scatterometry.
But, mid-infrared laser suppliers face many
unique challenges. Mid-infrared components
are expensive because of requirements for
exotic materials and coatings, cryogenic
cooling, and low manufacturing volumes.
Lasers have been bulky and the output
power of compact laser solutions has been
low. And, the new technologies face
challenges from other laser and nonlaser
technologies, such as Raman spectroscopy,
near-infrared laser and LED sources, lamps,
and non-optical approaches.
Now, new solutions in quantum cascade
and interband cascade lasers, GaSb diode
lasers and OPSLs, fiber lasers, solid-state
lasers, and compact OPOs promise to
expand sales into new applications. Other
innovations will also help the market, such
as inexpensive QEPAs, uncooled focal
plane arrays, and hollow-core optical fibers.
The report lists over 50 companies offering
lasers in the mid-IR range, spanning the
technologies listed above, as well as legacy
technologies. Well more than half of the
companies are headquartered in North
America.
With such a wide range of suppliers and
applications, the market is highly fragmented
and there is no overall leader. Some
industries prefer to bring differentiating
technology in-house, making several laser
suppliers targets for acquisiton.
Austin Scientifichas highest everorder bookOXFORD INSTRUMENTS subsidiary
Austin Scientific, has secured a major
order for 56 helium compressor systems
with a total value of $1,111k. The product
is a unique application that has
significant implications in the High
Brightness Light Emitting Diode
(HBLED) market, using helium gas as a
heat-exchange medium in high
temperature processes.
Austin Scientific also secured a further
significant order with a major
manufacturer of HBLEDs for 17
Cryopump systems with a total value
$205k, another very significant order for
the business. These two orders have
contributed to the business hitting its
highest order month in its 10 year history
as part of the Oxford Instruments Group.
General Manager of Austin Scientific,
Donald Gordon, said “This is a great
achievement for our business. HBLEDs
will undoubtedly play a huge role in
protecting our environment in the future,
and I am delighted that our products
have been chosen to support this
growing market. Everyone here has
contributed to this success and I
congratulate them.”
Austin Scientific supplies, refurbishes
and services cryopumps and
compressors for the semi-conductor
industry, and is based in Austin, Texas
USA. It was recently won the best of
local business award in the Gas
Compressors category by the U.S.
Commerce Association (USCA) for the
second year running.
12 www.compoundsemiconductor.net October 2010
news � review
SETI and Kyma join Forces to
Develop High-Efficiency Deep
UV LEDs
SENSOR ELECTRONIC TECHNOLOGY
(SETI) has entered a Joint Development
Agreement with Kyma Technologies, of
Raleigh, NC, USA.
The collaboration is aimed at developing low
defect AlGaN substrates and high
performance optoelectronic and electronic
devices based on these substrates.
Under the agreement, SETI will centre its
device development efforts on next
generation high efficiency Deep UV LEDs
on these novel substrates as it grows its
markets in high power applications such as
water disinfection.
SETI claims to be the world’s only
commercial manufacturer of Deep UV LEDs
and LED lamps. With a product portfolio
from 240nm through 400nm SETI serves a
wide range of markets including sensing
and instrumentation.
The firm has recently announced the
development of high power single chip
LEDs exceeding 30 mW and with high
power lamps commercially available; SETI
has recently been experiencing rapid growth
in the disinfection/sterilization market.
“The LED performance improvements that
will be enabled by developments under this
Agreement will help us grow the foundation
we have already built in the disinfection
market” said President and CEO of SETI,
Remis Gaska, “and will maintain our position
as leaders in Deep UV LED products”.
Recently, SETI has successfully completed
a Small Business Innovation Research
(SBIR) Phase I program by the National
Science Foundation to develop a prototype
of a commercially viable all-LED based
portable water disinfection system.
Kyma Technologies is a leading supplier of
crystalline III-nitride semiconductor materials
including GaN and AlN. Each
semiconductor device layer stack has a
preferred substrate composition. AlN and
GaN substrates are preferred for device
layer stacks which are AlN-rich and GaN-
rich, respectively.
For device layer stacks which have an
intermediate preferred lattice constant, such
as UV LEDs and certain next generation
high frequency and high power electronics,
AlGaN substrates are preferred.
“We appreciate the opportunity to work with
SETI to develop a low defect AlGaN
substrate product line, which should benefit
a range of advanced nitride semiconductor
device technologies,” stated Keith Evans,
President and CEO of Kyma Technologies.
Templates for Blue and UV LEDsGaN, AlN, AlGaN, InN, InGaN
World leaders in development of Hydride Vapour Phase Epitaxy (HVPE) processes and techniques for the production of novel compound semiconductors
• Templates
• Wafer size: 50mm-150mm
• Research grade InGaN wafers
• Custom design epitaxy
• Contract development
• Small and large batch quantities available
www.oxford-instruments.com/tdi3
Contact us now!
Email: [email protected] and Devices InternationalTel: +1 301 572 7834
Wide range of materials (GaN, AlN, AlGaN, InN and InGaN) on different sizes and types of substrates (sapphire or SiC)
See us at Semicon Europa Stand #4 220
October 2010 www.compoundsemiconductor.net 13
review � news
SHOWA DENKO K.K. has increased its
production capacity of blue LED chips at its
Chiba site to 340 million units per month,
from 200 million units per month. After
completion of expansion work in July, SDK
made a trial run to secure product quality
and stable operations. Commercial
operation has already started.
Demand for blue LEDs is expected to grow
around 10% a year on the average in
coming years due to increased use in such
applications as backlight for LCD TVs and
general lighting. SDK will promote technical
development to further increase output of
LED chips and improve production
efficiency, thereby providing high-quality,
high-performance products that fulfill
customers’ requirements.
SDK is aiming to reduce impact on the
environment and address such issues as the
depletion of resources. In its ultrabright
LED business, SDK will continue providing
energy-saving products in order to
contribute to sustainable development of
society.
SDK ups Blue LEDchip productioncapacity
smaller package size,” said Markus
Vockenroth, managing director, MAL Effekt-
Technik GmbH. “The XLamp ML-E LED was
the perfect combination of price and
performance for our application.”
The XLamp ML-E delivers lighting-class
performance in applications where a
smooth, uniform appearance is required,
such as LED fluorescent tube replacement,
ceiling-mounted panel lights and under-
cabinet lighting. Unlike other low-power
LEDs originally developed for consumer
electronics and backlighting applications,
the XLamp ML-E delivers the segment-
leading color binning, efficacy, thermal
resistance and reliability required for
luminaires and bulbs.
“The ML-E offers the lighting design
community a simple and affordable solution
for a major portion of the solid state lighting
market,” said Paul Thieken, Cree, director of
marketing, LED Components.
Cree Brings Lighting-Class LEDs to the Market
Cree is raising the standard for half-Watt
LED devices with the commercial availability
of its XLamp ML-E LED. The lighting-class
XLamp ML-E provides lighting designers
with a compact and cost-effective solution
for distributed LED arrays that can enable
them to meet the stringent U.S.
Environmental Protection Agency ENERGY
STAR performance criteria.
“When we set out to build our new linear
light engine, we required the efficacy and
reliability of XLamp LEDs, but wanted a
14 www.compoundsemiconductor.net October 2010
news � review
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JP SERCEL ASSOCIATES, a manufacturer
of laser scribing and laser lift-off (LLO)
systems for LED production, announced
that their 2010 shipments of laser
processing systems for LEDs is up 250% in
the first 3 quarters of 2010 from 2009
shipments.
The increasing demand for high throughput
266nm front side scribing tools for sapphire,
and HB LED wafers is being driven primarily
by major Taiwanese and Korean
manufacturers.
Founder and Chief Technical Officer of
JPSA, Jeffrey Sercel said, “Our 266nm front
side scribing continues to dominate the
market because we are able to provide LED
manufacturers higher throughput systems
that enable more die to be packed onto
each wafer. The increased die density and
reduced damage from the laser scribing
produces significantly higher yields than
mechanical or saw dicing methods. To
maintain our strong market presence, we
continue to develop advanced processes in
both scribing and laser lift-off applications,
and expect these applications to lead the
way for the LED market.”
JPSA’s recently released automation
platform for the IX 6100 laser scribing and
JPSA exceeds laser system
shipments in 2010 by 250%
laser lift-off systems is also shipping to LED
manufacturers. The new wafer load and
unload automation module, the IAP
(Integrated Automation Platform), provides
customers with dual-cassette wafer ports,
further streamlining the manufacturing
process, and increasing yields.
For continued development of advanced
micromachining processes and production
space, JPSA is in the final stages of
expanding their Manchester, NH
headquarters.
The completion is scheduled for October
2010 and will also provide state-of-the-art
clean rooms, R&D laboratories, and
ergonomic office space to accommodate
growing customer service and engineering
teams.
Long De Xinorders systems forGaN HB blue LEDproductionAIXTRON AG have announced an order for
two further CRIUS 31x2-inch configuration
deposition systems from Long De Xin. A
company based in the PR China, Long De
Xin placed the order during the second
quarter of 2010 with both systems
scheduled for shipment in the third quarter
of 2010. They will be used for the
manufacture of GaN ultra-high brightness
(UHB) blue LEDs.
The local AIXTRON support team will
commission the new reactors at the new
Long De Xin facility at their mainland China
production plant.
Mr. Jay Lin of Long De Xin comments,
“Since the demand for our blue LEDs has
been continuously growing we now have to
significantly increase our production
capacity. As we have found, the AIXTRON
CRIUS ives up to its worldwide reputation
for excellent process characteristics such as
uniformity and efficiency becoming crucial
for high-end HB LED production. My team
is awaiting the arrival of the systems and
looking forward to sharing the experience of
their technical support team.”
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October 2010 www.compoundsemiconductor.net 17
femtocells � industry
Anadigics attacks the femtocell market
with BiFET power amplifiers
The emergence of 4G smartphones is placing a tremendous
strain on mobile carriers. But this can be relieved by
adding femtocells to the network that are built
around customized high performance
power amplifiers, such as the
portfolio of products being
unveiled by Anadigics,
argues the company’s
Joe Cozzarelli.
Smartphones such as the Samsung Epic 4G and
the Apple iPhone are spawning a new generation
of gadget lovers. Armed with such a device, it is possible
to dip in and out of a vast array of applications while
socially networking any time, anywhere.
Thanks to these alluring attributes, smartphone sales are
rocketing, and now account for one-fifth of all handset
purchases. The owners of these cutting-edge devices are
exchanging more and more data as time goes by, so it is
not surprising that mobile operator networks are creaking
under increasing strain.
Today’s networks are built
around a traditional infrastructure
model, which involves blanket deployment of macrocells
to a geographic area. Any gaps that the macrocells
cannot cover are filled with microcells. Regardless of the
local cell technology, calls tend to be routed to their
destinations through either terrestrial T1 lines or
microwave backhaul, which are typically leased by the
network operator.
However, even with this extensive and costly infrastructure
in place, many people have either poor or no coverage in
their homes and offices. Small cell solutions offer
significant relief to this problem.
Complementing today’s networks with small cells, and
femtocells in particular, is the best way forward from both
an economic and quality-of-service perspective. By
placing coverage exactly where it’s needed, the mobile
operators will be able to keep pace with the growing
customer demand and redirect backhaul traffic to the
user’s internet. Imagine a network where the user’s
sessions are almost always open. These cells are an
attractive option for both upgrading the existing 3G
network infrastructure and for deploying 4G. By adding
hundreds of thousands of small local cell sites, users will
enjoy great coverage in their homes, shops or businesses.
Left: This May
Anadigics
introduced its
first two power
amplifier
modules for the
femtocell
market. These
single-ended
amplifiers
feature InGaP-
based HBTs
and produce an
average power
of 24.5 dBm
18 www.compoundsemiconductor.net October 2010
industry � femtocells
The femtocell market is expected to expand to
approximately 49 million access points by 2014,
according to the industry organization Femto Forum. By
then 114 million users across the globe will be accessing
mobile networks via femtocells. Considering that these
small cells contain all the functional elements of a
traditional base station, the importance of the RF power
amplifier (PA) module becomes apparent.
To enjoy significant commercial success in this growing
market, the femtocell design must balance features,
functionality and pricing. For the PA, these requirements
translate to characteristics that include exceptional RF
and DC performance, multi-mode support, multi-standard
support and reliability. The biggest factor that influences
all of these characteristics is the semiconductor process
used to manufacture the PA itself.
Going with GaAs GaAs-based chips are employed in the vast majority of
mobile handsets, as well as many components for low- to
mid-power infrastructure. By building devices around this
material it is possible to create amplifiers delivering great
performance at competitive prices, and there is every
reason to believe that this material will be widely used to
build the amplifiers deployed during the build-out of 3G
and 4G networks.
For the last ten years or so most PAs have been built from
GaAs-based HBTs. Initially these transistors combined
GaAs with AlGaAs, but more recently alternatives
employing the pairing of GaAs and InGaP have been
introduced that offer superior performance.
At Anadigics, which is based in Warren, NJ, we have built
upon the huge success of the InGaP/GaAs HBT. Our
InGaP-Plus process combines bipolar and FET devices
on the same GaAs die, a move that allows features
usually residing off of the chip to be integrated into
conveniently sized, surface mount parts. The upshot is
that switches, step attenuators, power detectors, and
voltage regulators are commonly found in our PAs.
Pioneering RF PerformanceWe are currently designing a family of balanced and
single-ended power amplifier modules for use in
femtocells, picocells and in-home customer premises
equipment. Each of our modules is specifically designed
to deliver optimal performance in one or more of the
several popular frequency bands used by wireless
carriers. While specific features vary from module to
module and are based on the target application, the
design approach for each is similar.
The availability of a family of devices offers significant
advantages to design teams, which may be tasked with
Figure 1. Anadigics has recently developed the AWB7227 power amplifier
module with a rated power of 27dBm. This balanced design that is slated
for release later this year can be used to amplify the waveforms of the
most demanding air interfaces such as CDMA, WCDMA, and LTE. When
driven with a WCDMA waveform – test mode 1, 64 channel waveform,
and a 10.5 dB peak-to-average ratio – this high-performance amplifier has
margin to the ACOP requirement
Figure 2. The AWB7227 amplifier is capable of supporting multiple
carriers, a feature that can be useful in certain deployment scenarios. Each
carrier represents a group of users operating at a particular frequency.
Here, the device has been subjected to 2 WCDMA Test Mode 1, 64
DPCH carriers at maximum separation
October 2010 www.compoundsemiconductor.net 19
femtocells � industry
most demanding conditions, such as a ‘Test Mode 1’, 64-
channel waveform with a PAR of 10.5 dB, there is
headroom to the standards requirements. Figure 1 shows
there is performance margin to the adjacent channel
power (ACP) requirement, so there is no need to back-off
the PA from its rated power to meet the ACP requirement
at the antenna. Additionally, the module has integrated
matching networks so it’s extremely easy to use.
The AWB7227 is also capable of supporting multi-carrier
operation (see Figure 2). This provides deployment
flexibility to mobile operators by providing handoff options.
This feature will become even more important as the
number of femtocells increases.
Future proof technologyAs air interfaces evolve, the associated technology must
keep pace. The PA module is certainly affected by these
providing femtocell products that implement different
standards and operate over different frequency bands.
PA module designers want amplifiers that combine
linearity with adequate RF power for good coverage and
the capability of handling high capacity waveforms with
high peak-to-average ratios (PAR). The PAs that we
produce excel on all these fronts, uniting high power with
outstanding linearity, plus good thermal performance for
high reliability. As expected, these products draw on the
many years of experience that we have in developing PAs
for mobile handsets and broadband infrastructure
products.
One of our primary goals is to create modules that
combine extremely linear performance with a full
complement of functional integration. To realize this
ambition, we exploit the native efficiency and broadband
capabilities of GaAs devices, and turn to state-of-the-art
RF circuit simulation and thermal analysis tools to design
the circuitry.
Since small cell products are available in several transmit
powers, we developed single-ended and balanced PA
modules with common features for each of the popular
wireless bands. Earlier this year we released our first PAs
for the small cell market, the AWB7123 and AWB7127, a
pair of singled-ended parts with average powers of
+24.5 dBm.
Before the year is out we will launch balanced equivalents
of these modules. These two additions - the AWB7223
and the AWB7227 - operate at frequencies centered on
1.9 GHz and 2.1 GHz, respectively. They deliver a linear
output of +27 dBm, which is more than adequate to cover
a home or small office space. The modules operate at 4.5
V, and can handle a high peak-to-average ratio (PAR)
waveform, making them ideal for networks employing
CDMA, WCDMA or LTE technology. All of these
products take advantage of the capabilities of our
patented InGaP-Plus technology.
The remainder of this article will focus on the higher-
frequency, balanced PA module: the AWB7227.
Measurements show that this device can deliver a high
level of performance when driven with a WCDMA signal
(see Figure 1). Even when this module is driven with the
To prevent the AWB modules from becoming ineffective as the latest standards are
deployed, we have designed them with the future in mind. Thanks to this approach,
we have enabled the creation of femtocells that can adapt to standards and
support migration and growth strategies.
Figure 3. When designing the AWB series, the engineers at Anadigics
had one eye on the future. As mobile carrier technology evolves, it is
likely that the frequency division duplex LTE protocol will be used widely.
The AWB7227 is capable of making this transition, as shown by this
measurement with a 10 MHz, fully filled 64 QAM (50RB) test model
20 www.compoundsemiconductor.net October 2010
industry � femtocells
changes. To prevent the AWB modules from becoming
ineffective as the latest standards are deployed, we have
designed them with the future in mind. Thanks to this
approach, we have enabled the creation of femtocells that
can adapt to standards and support migration and growth
strategies.
One of the technologies that is on the horizon is
frequency division duplex LTE, which is compatible with
our AWB7227. Figure 3 shows the AWB7227
performance with an LTE waveform. Again, there is a
healthy margin to the performance required by the
standard. When building an infrastructure, particularly one
based on femtocells, it is critical to deploy robust
components that are capable of reliable operation for
many years. This means that power amplifiers must have a
long mean-time-to-failure (MTTF). The MTTF is primarily
dictated by the semiconductor material itself and the
junction temperature.
Our PA modules are designed for long operating life. They
employ HBTs featuring the ternary material InGaP, which
have a very strong track record in creating PAs that
combine high reliability with extremely high efficiency (see
Figure 4). This pairing of attributes has made this type of
module a very popular choice for many years in applications
demanding similar power levels to those used in femtocell
networks.
Figure 5 shows the thermal scans of the AWB7227 when
operated at its rated voltage and driven to its rated power
with a CW signal. The measured die junction temperature
is just 115 oC, which translates to an extremely high MTTF.
The AWB series has been designed to do an excellent job
of converting DC input power to usable RF transmit
power. Considering that the PA remains one of the key
consumers of power in any base station, efficiency is an
extremely important parameter. Thanks to the high
efficiency of the AWB7227, the overall power
consumption of the femtocell will be more manageable,
supporting ‘green’ initiatives and enabling other key
femtocell features such as battery back-up.
By carefully selecting materials and applying sound
design principles, we are continuing to build a growing
portfolio of high-performance PA modules that should
lead to the construction of higher-performance
femtocells. As the small cell market for both service
providers and consumers grow, our AWB series of PA
modules will provide a catalyst for ubiquitous coverage
from 3G and 4G wireless networks while delivering a
high quality of service.
Figure 4. The power-added efficiency of the AWB7227
is best in class, thanks in part to the inclusion InGaP
Figure 5. A thermal scan of the AWB7227 power amplifier module reveals
a junction temperature of just 115 oC when the device was operated at its
rated voltage and driven to its rated power with a CW signal
Our PA modules are designed for long operating life. They employ HBTs featuring
InGaP, which have a very strong track record in creating PAs that combine high
reliability with extremely high efficiency
October 2010 www.compoundsemiconductor.net 21
III-V microelectronics � technology
Fraunhofer IAF targets terahertz
circuitsGate scaling is the key to penetrating the depths of the sub-millimeter-wave
frequency range. It improves RF performance, empowering active electronics at
these ultra-high frequencies, say Axel Tessmann, Ingmar Kallfass and Arnulf
Leuther from Fraunhofer IAF.
Aband of researchers around the world are united in
their quest to build faster and faster circuits. If they can
fulfill their dream, they will not only be able to investigate
widely unchartered regions in the high millimeter, sub-
millimeter and terahertz frequency range, but also start to
develop novel systems operating in these spectral
domains. Opportunities exist for spectroscopy in these
spectral ranges along with trials of communication at
staggering bit rates. What’s more, at terahertz frequencies
in particular, there is the chance to fabricate incredibly
compact imaging systems with tiny antennae operating at
breathtaking bandwidths.
The most promising device for reaching these incredibly
high frequencies is the MMIC. Unlike rival diode
electronics and optical technologies, this miniature
integrated circuit offers an incredibly attractive
combination of value-for-money, mass manufacturability,
small size and on-chip multi-functionality.
Many approaches can be taken to building a high speed
transistor, and at Fraunhofer IAF we are pursuing an
InAlAs/InGaAs metamorphic HEMT (mHEMT)
architecture. This design has much to recommend it: a
great deal of freedom, in terms of epitaxial design;
outstanding electrical performance; and an easy-to-
handle, underlying GaAs substrate.
We have been able to successfully scale this device down
to gate-lengths of 20 nm, and can now offer circuit
designers a tremendously fast transistor. Cutoff-
frequencies, fT, exceed 600 GHz and the fmax value is well
beyond 900 GHz. If these transistor speeds are to be
really useful, they need to be exploited at the circuit level.
To this end, we are continuously refining our passive
components, the transmission line approach of the entire
MMIC process, and the waveguide packaging technique
for ultra high frequency operation. Our success has been
built on long-standing expertise in the design, fabrication
and packaging of MMICs based on metamorphic HEMT
technology. The virtues of this class of transistor stem
from its metamorphic buffer, which allows the use of
substrates made from GaAs, rather than InP. These are
larger, cheaper, and less brittle. In addition, mHEMTs
grown on GaAs have a higher degree of flexibility for
heterostructure growth, thanks to a lift in restrictions
related to the lattice parameter.
The upshot of all of this is that we can perform
successful epitaxial growth of InAlAs/InGaAs layers with
very high indium concentration on 4-inch GaAs. The 1
μm-thick quaternary buffer that we employ begins with
an Al0.52Ga0.48As layer, and the group III element
gallium is linearly exchanged for indium.
Figure 1. Smaller gates can speed transistors. Between 2001 and 2010
Fraunhofer IAF made great strides in this direction, reducing the length of
its gates employed in its InAlAs/InGaAs metamorphic HEMT technology
22 www.compoundsemiconductor.net October 2010
technology � III-V microelectronics
delivered superior charge confinement. In turn, the transit
frequency, fT, of these mHEMTs has rocketed from
220 GHz for the 100 nm mHEMTs to 515 GHz for the 35
nm gate length devices. The faster variant can hit a drain
current, Id, as high as 1600 mA/mm at a drain voltage of
1 V, thanks to a very low source resistance of only
0.1 Ω.mm. Both of the mHEMTs feature a 250 nm-thick
MOCVD-deposited SiN layer, which is employed in all our
devices.
There is more to realizing an IC with terahertz capability
than producing super-fast transistors. Adapted passive
circuit elements are essential for confining
electromagnetic fields and suppressing unwanted
substrate modes. To meet these needs we employ a
grounded coplanar waveguide topology with coplanar
transmission lines on the MMIC front side, connected to
grounded backside metallization with miniaturized
through-substrate vias.
This topology also provides a low source inductance of
the active devices, along with compact transmission line
dimensions. The crosstalk within the circuits is
minimized by cutting the coplanar line ground-to-ground
spacing to 14 μm. This, in turn, slashes chip size. To
suppress substrate modes, a small spacing between
the through substrate vias is necessary. By reducing the
size of the vias from 35 to 20 μm, enough of them can be
accommodated in the miniaturized MMIC topology. The
final substrate thickness is 50 μm.
Figure 2. Reduction in the gate size of Fraunhofer
IAF’s transistors has been accompanied by
adjustments to device design. This is evident in the
layer composition of the 50 nm (a) and the 35 nm (b)
mHEMT heterostructure. The 35 nm mHEMT layer
sequence includes a double-side doped, single
In0.80Ga0.20As channel to avoid short channel effects
Figure 3. Fraunhofer IAF has fabricated a MMIC chipset for broadband
performance at 300 GHz. This is based on active circuit concepts and
employs 100 and 50 nm gate-length mHEMT technology. The chipset
incorporates a low-noise amplifier, resistive mixer with integrated
frequency-doubler, LO power amplifier and frequency-multiplier-by-six. The
role of the balanced active frequency-multiplier-by-six is to provide 0 dBm
of output power in the 110 to 152 GHz range. When directly driven by the
multiplier output power, the combination of frequency doubler and resistive
mixer produces a conversion loss of 20 dB. With the intermediate LO
power amplifier, conversion loss is reduced to only 12 dB across the 260-
308 GHz frequency range. The LNA provides pre-amplification by 20 dB
at 290 GHz with an estimated noise figure of 7.5 dB. This takes the
overall receiver performance to a maximum conversion gain of 8 dB.
Towards terahertzArmed with an InGaAs channel, these HEMTs are the
most advanced device technology for building the
upcoming terahertz monolithic integrated circuits (TMICs).
That’s because they deliver high transistor gain at very
high frequencies and produce the lowest noise figure of
any active device technology. The key to these high
speeds has been a cut in gate length (see Figure 1).
Advancing beyond 200 GHz while maintaining reasonable
gain was not trivial - it demanded proper scaling of the
entire process parameters.
So at every technology node adjustments were made to
the scaling rules of the gate-to-channel separation, source
resistance, and electron density in the channel.
Increasing the indium content in the InGaAs channel has
also helped to speed our mHEMTs (see Figure 2).
Ramping the indium content to its upper limit to create a
pure InAs film has increased electron mobilities and
October 2010 www.compoundsemiconductor.net 23
III-V microelectronics � technology
These processes have been used to build a mHEMT
portfolio featuring 100, 50 and 35 nm gate length
technologies, which can be used to fabricate circuits
operating at up to 220, 340 and 500 GHz, respectively. A
20 nm gate length process is currently under
development, which will replace the 35 nm technology
and enable the design of novel terahertz ICs operating at
750 GHz and beyond.
How fast?In response to the fabrication of faster transistors by our
team and others around the world, commercial suppliers
are starting to develop and fabricate frequency extension
modules for accurate S-parameter measurements of ICs
and modules up to approximately 1.1 THz. In addition, RF
probes are now available for frequency bands between
0 and 500 GHz.
Although these efforts are welcomed, there are still major
challenges associated with ultra-high-frequency
measurements. For example, increases in operational
frequency come at the penalty of a reduction in the
dynamic range of these measurement systems. This
increases the noise floor, complicating system calibration,
which in turn affects the measurement of both active
devices and passive circuit components. The
consequence is that as we push further into unchartered
frequency domains, we have to devote far more time to
accurate calibration, testing and device model extraction
in order to ensure successful circuit design and
fabrication.
In addition to small-signal amplifiers, we are developing all
of the required functional blocks for transmitters and
receivers. This ever-expanding portfolio encompasses
frequency generation and multiplication, power
amplification and frequency conversion.
One example of our efforts is an all-MMIC-based
broadband heterodyne receiver front-end spanning 268 -
306 GHz (see Figure 3). The wideband receiver is formed
by a monolithic chip set that combines a cascading low-
noise amplifier; resistive mixer with integrated frequency-
doubler; LO power amplifier; and frequency-multiplier-by-
six. The result is a chip that delivers up to 8 dB of
conversion gain and has a noise figure of 7.6 dB. These
performance figures rival those of state-of-the-art Schottky
receivers.
Recently, we have focused our development on sub-
millimeter-wave ICs and modules for operation above
300 GHz. This hinges on the realization of TMICs, which
is the short-term target. Progress in this direction includes
the fabrication of a 320 GHz mHEMT amplifier package
with a waveguide module in split-block configuration (see
figure 4). The MMIC is thinned down to a substrate
thickness of 50 μm, allowing the use of very short bond
wires. This ensures low parasitics and low loss. To
increase operational reliability, the power supply was
integrated into the module.
Figure 4. Fraunhofer IAF’s sub-millimeter-wave
amplifier module in split-block technology. The
dissection plane divides the input and output
rectangular waveguides along the centerline of the
longer side. The monolithic 50 nm gate length amplifier
circuit is mounted between two microstrip lines
realized on 50 μm-thick quartz substrates.
These two lines are serving as waveguide-to-microstrip
transitions
Figure 5.
Fraunhofer IAFs
mHEMT
amplifier
modules
produce a
maximum gain
of 21 dB at
300 GHz.
Small-signal
gain exceeds
19 dB
between 295
and 320 GHz
Figure 6. The
four-stage,
460 GHz
mHEMT
amplifier
S-MMIC
employs
transistors with
a gate width of
only 2 x 5 μm.
Die size is only
0.37 x 0.63 mm2
24 www.compoundsemiconductor.net October 2010
technology � III-V microelectronics
Further reading
I Kallfass et al. 2009 Proc. of SPIE 7485
A Leuther et al. 2010 IPRM Technical Digest 425
A Tessmann et al. 2010 IMS Technical Digest 53
Measurements of this amplifier reveal that it delivers a very
flat gain characteristic. Linear gain exceeds 19 dB from
295 to 320 GHz, and it hits a maximum gain of 21 dB at
300 GHz (see Figure 5).
We have also produced a handful of amplifier MMICs with
remarkable bandwidth and low noise figures for operation
in frequency bands between 220 and 500 GHz. These
amplifiers should help to spur development of high
resolution imaging systems, wireless ultra-high-capacity
communication links and sub-millimeter-wave spectroscopy.
Figure 7.
On-wafer
measured
S-parameters
of a four-stage
mHEMT
amplifier
SMMIC. Small
signal gain of
more than
16 dB is
realized at
460 GHz.
One example of this type of amplifier is a four-stage,
460 GHz S-MMIC (see Figure 6). In this case, the amplifier
was designed to deliver high small-signal gain and low
noise. It fulfills these goals, delivering a peak gain of
16.1 dB at 460 GHz when driven at a drain voltage of
Vd = 1 V, a gate voltage of Vg = 0.2 V, and a drain
current of 23 mA (see Figure 7). Small-signal gain
exceeded 13 dB across the range 433-465 GHz.
Amplifiers such as this, along with others that we have
showcased in this article, are proof of our expertise in
high-speed transistors and accompanying MMIC and
packaging technology.
These recent scaling advances, which re-enforce our
position as the leading pioneer of high-speed devices
and circuits within Europe, have equipped our mHEMTs
for terahertz operation and are paving the way for
terahertz ICs.
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LEDS WILL CHANGE THE
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LEDS WILL CHANGETHE WORLDHigh-Brightness LEDs are Critical Semiconductor Technologies for energy efficiency, safety and next generation displays. Improvements in cost per lumen and light-ing quality of high-brightness light emitting diodes (HB-LEDs) parallel those of Moore’s Law. Like Moore’s Law, reaching the full potential of LEDs requires the global LED manufacturing supply chain to collaborate on technology roadmaps and industry standards to reduce costs and spur innovation.
SPEED UP THE PROGRESSJoin SEMI, the global trade association that will help you change the world— and com-pete in the lucrative market of LEDs at the same time. SEMI regularly holds International Standards and EHS meetings to address issues critical to the LED manufacturing sup-ply chain. In 2010, SEMI will hold LED events
in six countries.
April 25-29, 2011 • San Francisco, California
Sy
mp
oS
ia
www.mrs.org/spring2011
2011 MRS Spring Meeting Chairs
Ping Chen Dalian Institute of Chemical Physics [email protected] [email protected]
�
Mat
eria
ls r
esea
rch
soci
ety
Ad
van
cin
g m
ate
ria
ls.
Imp
rovi
ng
th
e q
ua
lity
of
life
.
MateRialS foR eneRgy and SuStainabilityA Amorphous and Polycrystalline Thin-Film Silicon Science and TechnologyB Third-Generation and Emerging Solar-Cell TechnologiesC Advanced Materials Processing for Scalable Solar-Cell ManufacturingD Compound Semiconductors for Energy Applications and Environmental SustainabilityE Energy Harvesting—From Fundamentals to DevicesF Renewable Fuels and NanotechnologyG Complex Oxide Materials for Emerging Energy TechnologiesH Electrochromic Materials and DevicesI Nanoscale Heat Transfer—Thermoelectrics, Thermophotovoltaics, and Emerging Thermal DevicesJ Protons in SolidsK Frontiers of Solid-State IonicsL Interfacial Phenomena and In-situ Techniques for Electrochemical Energy Storage and ConversionM Nanostructured Materials for Energy StorageN Recent Developments in Materials for Hydrogen Storage and Carbon-Capture Technologies
eleCtRoniC and PhotoniC MateRialSO Materials, Processes, and Reliability for Advanced Interconnects for Micro- and NanoelectronicsP Interface Engineering for Post-CMOS Emerging Channel MaterialsQ New Functional Materials and Emerging Device Architectures for Nonvolatile MemoriesR Phase-Change Materials for Memory and Reconfigurable Electronics ApplicationsS Plasma-Assisted Materials Processing and SynthesisT High-Speed and Large-Area Printing of Micro/ Nanostructures and DevicesU Nuclear Radiation Detection MaterialsV Rare-Earth Doping of Advanced Materials for Photonic ApplicationsW Recent Progress in Metamaterials and Plasmonics
nanoMateRialS and nanoteChnologyY Functional Two-Dimensional Layered MaterialsZ Nanoscale Electromechanics of Inorganic, Macromolecular, and Biological SystemsAA Micro- and Nanofluidic Systems for Materials Synthesis, Device Assembly, and Bioanalysis II
BB Nanoscale Heat Transport—From Fundamentals to DevicesCC Hybrid Interfaces and DevicesDD Quantitative Characterization of Nanostructured MaterialsEE Semiconductor Nanowires—From Fundamentals to ApplicationsFF Surfaces and Nanomaterials for Catalysis through In-situ or Ex-situ StudiesGG Titanium Dioxide NanomaterialsHH The Business of Nanotechnology IIIII Ion Beams—New Applications from Mesoscale to Nanoscale
oRganiC and bioMateRialSJJ Biological Hybrid Materials for Life SciencesKK Microbial Life on Surfaces—Biofilm-Material InteractionsLL Biomimetic Engineering of Micro- and NanoparticlesMM Organic Bioelectronics and Photonics for Sensing and RegulationNN Electronic Organic and Inorganic Hybrid Nanomaterials—Synthesis, Device Physics, and Their ApplicationsOO Synthesis and Processing of Organic and Polymeric Materials for Semiconductor ApplicationsPP Engineering Polymers for Stem-Cell-Fate Regulation and Regenerative Medicine
geneRal MateRialS SCienCeQQ Carbon Functional InterfacesRR Fundamental Science of Defects and Microstructure in Advanced Materials for EnergySS Forum on Materials Education and Evaluation— K-12, Undergraduate, Graduate, and InformalTT Laser-Material Interactions at Micro/NanoscalesUU Crystalline Nanoporous Framework Materials— Applications and Technological FeasibilityVV Future Directions in High-Temperature Superconductivity—New Materials and ApplicationsWW Multiferroic, Ferroelectric, and Functional Materials, Interfaces, and HeterostructuresXX Computational Studies of Phase Stability and Microstructure EvolutionYY Computational Semiconductor Materials Science
C A LL FO R PA PE R S
Chang-beom eom University of Wisconsin- Madison [email protected]
Samuel S. Mao Lawrence Berkeley National Laboratory [email protected]
Ryan o'hayre Colorado School of Mines [email protected]
abstract Deadline • November 2, 2010
Solutions for HIGH BRIGHTNESS LEDManufacturing
Nano Imprint Lithography for beam shaping and enhanced light extraction
Handling and processing of thin and bowed wafers
Wafer bonding for layer transfer
Optical lithography and resist processing solutions
www.EVGroup.com
October 2010 www.compoundsemiconductor.net 27
interview � RFMD
RFMD opens the doors of
its MBE facility
Diversification: that’s the central pillar of RF Micro Devices’ growth strategy.
To continue to execute on that front it is opening up its MBE facility and starting to
offer various services that include shipments of arsenic- and phosphorous-based
epiwafers. Richard Stevenson investigates.
R F Micro Devices is renowned for its
manufacture of power amplifiers. In the late
1990s it convinced handset makers to turn away from
MESFET-based amplifiers and switch to its HBT-based
variant. Since then it has gone from strength to strength
to become one of the world’s largest manufacturers of
power amplifiers, which it churns out in-house on a 6-inch
line equipped with multi-wafer MBE tools.
While there is no denying that RFMD’s fame derives from
its manufacture of billions of HBTs at its Greensboro, NC,
headquarters, it is wrong to think of this company as just
a captive GaAs chipmaker. Since 2003 it has been
outsourcing growth of InGaP HBTs – it now has several
established suppliers of MOCVD-grown epiwafers – and
during the last few years it has added another string to its
bow, GaN. The company continues to expand its portfolio
of wide bandgap RF products, and last year it started to
offer foundry services for this technology, including
fabrication of GaN-on-SiC wafers to customer-specific
circuit designs.
The company’s diversification strategy has taken another
significant stride this year: The introduction of MBE-
related epitaxial products and services, including ultra-
high vacuum cleaning services. Profitable new revenue
streams could result from this move, leading to a good
return on the company’s substantial investment in capital
equipment.
“Our offerings include working with customers to develop
epitaxial structures and MBE growth conditions; the
delivery of epiwafers grown to exact customer
specifications; and designing epitaxial DOEs [design of
experiments],” explains Robert Van Buskirk, president of
RFMD’s multi-market products group.
RFMD’s MBE services are available to all. There is no
minimum order, so start-ups and small companies will not
be put off working with this RF giant. And RFMD’s proven
pedigree in high volume manufacturing makes it an
appealing option for far bigger players looking to off-load
epiwafer growth, or qualify an external material supplier
that can supplement internal manufacture during peak
periods.
The battle aheadIf RFMD is to have significant success in this new
venture, it will have to tender and win MBE-based
epiwafer supply contracts. The strongest competition will
surely come from IQE, an epiwafer supplier with large
MBE facilities in Singapore and Bethlehem, PA, that has
experience in producing material for RF applications in
high volume, thanks in part to its contract with Anadigics.
The Greensboro outfit is certainly up for the challenge of
competing in the epiwafer supply market. It is no stranger
to high-volume manufacture, and Van Buskirk points out
that the company can draw on its experiences associated
with developing several generations of epitaxial structures
that have been instrumental in the creation of one of the
most successful RF companies in the world.
An RFMD
technician
loads
substrates in
preparation for
epitaxial growth
28 www.compoundsemiconductor.net October 2010
RFMD � interview
What is certain is that RFMD’s new venture will get off
the ground. Over the years the company has had several
inquiries and engagements for MBE products and
services, including the ones that they are offering, and this
interest will not diminish now.
A significant proportion of RFMD’s revenue from its new
venture is likely to come from the sale of arsenic and
phosphorous-based epiwafers. These structures can be
grown on 4-inch or 6-inch GaAs substrates, which can
either be supplied by the customer, or purchased from
RFMD. “We do not have the capability for nitride growth,
but beyond that limitation, we are open to any epi
structure,” says Chris Santana, director of the company’s
MBE operations. According to him, RFMD has experience
in growing and developing many different types of
structure, including metamorphic designs, BiHEMTs,
MOSFETs and even optoelectronic material such as
VCSELs.
RFMD’s introduction of a GaN-based foundry service in
2009 has provided a great stepping-stone for this year’s
foray into MBE services. “We now have all the aspects of
a full-service, commercial turn-key foundry in place –
including purchasing and IP agreements, work-flow
procedures, and web-based customer support processes
– and we can quickly tailor those commercial business
processes and systems to our MBE-based service,”
explains Van Buskirk.
Customer servicesAlthough GaN and MBE foundry customers can just
instruct RFMD to supply wafers to their specifications,
there is more help on hand if they want it. For example, in
RFMD’s GaN foundry, customers can tap into the
company’s design kits that are supported by industry
standard design software and device models. What’s
more, it is normal for RFMD’s engineers to interact with
customers in the final stages of their circuit design efforts
to make sure that customer designs do not violate any in-
house design rules or layout services, as documented in
RFMD’s design kits. “However, while we offer a wide
range of GaN-based proprietary products, we do not offer
circuit design services for our foundry customers,”
explains Van Buskirk.
Santana claims that his team will be even more flexible
when it comes to MBE structures and profiles. In this
case, so long as they can support the customization
required, the engineers will be willing to help to develop
epiwafer designs needed to develop a product. “We will
be happy to engage customers in this technical dialogue.”
Any company weighing up the pros and cons of working
with an epiwafer supplier will demand the protection of
their intellectual property. RFMD can assure customers of
this, and show them the plans put in place that draw on
its previous foray into foundry services. “We have
established robust firewalls within RFMD for our GaN-
based foundry service,” explains Van Buskirk. “Our
foundry service teams are separated from our internal
development teams, and RFMD employees at large
cannot access the IP or data for foundry services.”
There are times when customer-sensitive information has
to be transferred to RFMD employees, but this is
minimized, with technical data and information disclosed
on a ‘need-to-know’ basis. When a customer wants to
access design kits and models, they can do this through
an external, web-based portal that allows them to see the
status of their wafer fabrication orders.
Aside from IP issues, the big question for many customers
is how long it will take them to get their epiwafers. Van
Buskirk has some reassuring news for them: “We have
the industry’s fastest cycle times, and expect to use that
as a key performance discriminator in our foundry
service.” Cycle time commitments are already in place for
customers using RFMD’s GaN services, and they have a
clause in these contracts entitling the customer to a
discount if shipments are late.
Van Buskirk can also assure customers that they will not
lose out if RFMD has a substantial hike in orders for its
own GaAs chips. “We are committed to growing our
foundry services, and we have the installed capacity to
meet our internal needs and the needs of our potential
external foundry customers.” In fact, this installed capacity
is so large that it makes RFMD one of the world’s largest
MBE, GaAs and GaN wafer production facilities, claims
Van Buskirk.
The MBE facility at RFMD runs ‘24-7’, but it is only
staffed from 7 a.m. to 7 p.m. Automation allows the MBE
tools run through the night, with growth aborted if in-situ
RFMD’s
portfolio of
multi-wafer
MBE tools
includes
reactors built
by Veeco,
Riber and VG
October 2010 www.compoundsemiconductor.net 29
interview � RFMD
monitoring tools determine that the processes have
deviated beyond acceptable windows for production.
Customers can select the tool for epiwafer production
from a portfolio of MBE reactors: a Veeco Gen2K, which
has a 7 x 6-inch capacity; a Riber R7000 with identical
capacity; a Riber R6000, which can accommodate four 6-
inch wafers; and a single wafer, 6-inch tool, the VG V100.
RFMD equips these tools with state-of-the-art monitoring
apparatus. “Our MBE systems are outfitted with what we
believe to be the most effective tools at delivering quality,
consistent products,” claims Santana.
To ensure that the facility is run as efficiently as possible,
the company’s process engineers interlace growths for
the customers with those for internal production.
“However, if the customer chooses, we can enter into an
agreement that provides exclusive use of an MBE tool for
a period of time,” reveals Santana. In fact, RFMD has
already taken this type of arrangement with one of its
MBE foundry customers.
The Greensboro outfit has an impressive toolkit for
characterizing epiwafers. Alongside the more common
methods for determining material characteristics, such
as a Lehighton instrument for resistivity measurements
and an X-ray diffraction tool, the company can analyze
wafers with a multi-field Hall probe and a photoreflectance
technique.
“Multi-field Hall is primarily used to give the mobility and
carrier concentrations of the conductive layers in the epi,”
explains Santana. It can, for example, be used to
determine the mobility and carrier concentrations in both
the channel and the highly conductive cap layer of
pHEMT epiwafers. This is beneficial, because it eliminates
the need to grow a ‘capless’ calibration structure. “In
addition, it is also an excellent method for process
control,” argues Santana.
Photoreflectance, another non-destructive technique,
provides a qualitative measurement of HBT gain. Samples
are probed with a broadband light source, and insights
into the structure are gleaned by collecting and spectrally
analyzing light that has been reflected off of the many
interfaces of the transistor. The data from all of these
measurements can accompany material shipments to
customers. And if the customer wants the data collected
by the in-situ monitoring tools, including values for growth
rates and temperatures, this can be sent as well.
In short, it seems that RFMD is willing to stay as flexible
and accommodating as possible to meet the customer’s
needs. At present the only tasks that the company is not
prepared to do are to process GaAs wafers into chips
and package them. But even this may become an
option one day – after all, it certainly ties in with the
company’s goal of diversification. Will it do it? We’ll just
have to wait and see.
When RFMD launched in the early 1990s,
it had just one technology – the AlGaAs
HBT. Initially this was produced on 4-inch
wafers at TRW, but in 1997 RFMD
transferred the MBE process to its own
fabrication facility, known as fab 1. A larger
facility, fab 2, was added two years later, in
response to a rapidly growing order book.
During the last decade the company
expanded its technology. In 2002 it added
a second generation of AlGaAs HBT to its
technology portfolio, and soon after that it
started working towards the addition of
switches to its product mix. Initially these
were outsourced from the UK firm
Filtronic, but soon after RFMD started to
develop an in-house production process
and become less dependent on imports.
Further down the line RFMD acquired
Filtronic’s 6-inch fab line, which it now
uses to produce switches based on
epiwafers grown at Greensboro. Filtronic’s
line was equipped with two Veeco Gen2K
systems, but one has been shipped across
the Atlantic to support the foundry
business.
Today RFMD manufacturers exclusively on
6-inch GaAs, and uses MBE to produce
four generations of AlGaAs-based HBTs
and two generations of pHEMT. The latest
pHEMT combines switching
characteristics with amplification to create
products for WLAN.
The throughput
of MBE-grown
material at
RFMD has
climbed over
the last decade.
The dip in
2008 resulted
from a sharp
decline in
handset orders,
plus a move
from within that
industry to
slash inventory
levels. The
continuous line
shows actual
wafer output,
and the dashed
line is a linear
fit of this data.
RFMD’s long-standing affair with MBE
The RF Micro Devices MBE Facility is
located in Greensboro, North Carolina
From backlighting TVs to empowering mobiledevices and harnessing the sun’s energy,compound semiconductor chips are playing anever-increasing role in modern life. This is set to continue, but what will be the biggest breakthroughs over the next five years? Andwhat’s needed to tap into these new markets?
The CS Europe Conference, situated in the heartof Europe, will be exploring these issues andmany more. During this 1 day, dual trackconference, pioneering companies from aroundthe globe will give their take on the bestopportunities for compound semiconductors, andwhat has to be done to seize these opportunities.
If you want to learn from the insight of theseinsiders, be sure to book your place at CS Europe, which will be hosted in
Frankfurt, Germany, 22 March 2011.
Topics will cover, but not limited to: � LEDs for general illuminations �What’s needed from GaAs and GaN for
tomorrow’s wireless? � Visible lasers: brighter, more powerful and
greener? � How can optical chips keep pace with the
exponential rise in internet traffic? � Can concentrating photovoltaics fulfil its
promise and make the world a better place? � Compound and silicon converge � Hot Topics
WHAT NEXT FOR THE
COMPOUND SEMICONDUCTOR
INDUSTRY?
Contact:
T: +44 (0)2476 718 970
“Your challenge is met by someone else’s solution and
CSEurope aims to provide the platform that allows
the CS community to not just share ideas but
develop solutions in manufacturing and furthering
the reach of Compound Semiconductor devices.”
Klaus H. PloogKeynote Speaker
Professional Career: � Senior research scientist at University of Bonn and Research Center Juelich
� Senior research scientist/head of MBE Research Group/ Associate professor at
Max Planck Institute for Solid State Research in Stuttgart for 17 years.
� University professor of Materials Science at Darmstadt University of Technology
� Director of Paul Drude Institute for Solid State Electronics in Berlin
� University Professor at Physics Department of Humboldt University Berlin
Visiting research professor at:� NTT Electrical Communication Laboratories, Tokyo
� NTT Basic Research Laboratories, Tokyo
� Mitsubishi Central Research Laboratories, Amagasaki (Hyogo Prefecture)
� Kyushu Institute of Technology in Tobata/Kyushu
� Tokyo Institute of Technology, Tokyo
� Stanford University, Stanford
� Teikyo University of Science & Technology, Uenohara/Yamanashi
� “IBERDROLA Ciencia y Technologia” at ETSI Telecomunicacion (UPM), Madrid (Spain)
� Hokkaido University, Sapporo (Japan)
� National Sun Yat-Sen University, Kaohsiung (Taiwan)
� Waseda University, Tokyo (Japan)
� Waseda Institute of Advanced Studies, Tokyo (Japan)
� University of Western Australia, Crawley (Australia)
Awards:� Technology Transfer Award of Ministry of Research and Technology of FRG
� Award of Italian Physical Society (together with R.Cingolani, University of Bari)
� Philip-Morris Research Award (together with 9 colleagues of Max Planck Institute)
� IBERDROLA Ciencia y Technologia Award in Spain
� Max Planck Research Award for International Cooperation
� Eugen-and-Ilse Seibold Prize of German Research Foundation (DFG) for commitment to
promote understanding between Germany and Japan
� Order of Merit of the Federal Republic of Germany
� Tsung-Ming Tu Award of Taiwan National Science Council and Humboldt-Foundation
� Outstanding Reviewer of American Physical Society
A selection of the companies presenting include JDS Uniphase Corporation, Modulight, OMMIC, OSRAM, TriQuint, United Monolithic Semiconductors, TranSiC, and RFMD.
Klaus H. Ploog
Registrations open at:
www.cseurope.net
32 www.compoundsemiconductor.net October 2010
interview � EuroPIC
Europe backs a central
foundry for photonic
integrated circuits
High costs and long development times are impairing the chances of
success for small companies pioneering novel devices based on
photonic integrated circuits. To cater for these needs, Europe is funding
the creation of an InP foundry that will use generic processes to create
devices for multiple applications. Richard Stevenson discusses this
venture with the project’s two coordinators, David Robbins
from Willow Photonics and Meint Smit from the
Technical University of Eindhoven.
October 2010 www.compoundsemiconductor.net 33
EuroPIC � interview
Q Explain the motivation for creating a European
foundry for InP photonic integrated circuits?
AMS: What we’re trying to do is introduce into InP-
based photonics a similar foundry model to that
which is so successful in CMOS microelectronics.
I think it’s good to distinguish between what we call
custom foundries and generic foundries. A lot of fabs that
call themselves foundries offer to develop a process for
you, but with generic foundries, the process is
standardized. That’s new and it makes access to this
PIC technology much easier and cheaper.
There are two institutes that already offer that kind of
foundry service on a research basis: ePIXfab for silicon
photonics; and JePPIX (Joint European Platform for InP-
based Photonic Integrated Components and Circuits) for
InP. What we are talking about here is transferring the
JePPIX approach into industry. Hopefully a European PIC
foundry will exist in 2013.
Q The millions and millions of dollars poured into
PIC technology have not provided a great return
on investment. How will the European manufacturing
platform for photonic integrated circuits (EuroPIC)
change that?
ADR: Actually, the technology in these types of
photonic integrated circuits is having quite a lot of
commercial success. But this is only in the telecoms
arena, where there is enough money and drive to deliver
the integration needed to make those systems work.
One issue is that by and large the equipment suppliers in
the telecoms, which are very dedicated in their own
narrow commercial structures, don’t give access to their
fabs. However, even if they did, the cost of development
of the chips for someone else would be pretty horrendous.
Even custom fabs, which operate at a lower cost level, are
pretty expensive.
If we can develop along generic lines, PICs can become
much cheaper - maybe one or two orders of magnitude
cheaper. From there we can start to grow the market
volumes in other sectors.
MS: Another important point is that once you have the
platform technology and a lot of companies are using it, it
will be worth the effort of creating a dedicated design kit
and component library. Once you have that, you will
design to accurate models, speeding up the whole design
process and making it more accurate. That’s what has
happened in microelectronics. Photonics technology is
much too fragmented, with design software at a very
basic level compared to the electronics industry.
Q Once the foundry is up and running, who will be
its main users?
AMS: They will be University spin-offs and SMEs that
want to investigate the application of PICs in novel
or improved products, and also larger companies that can
develop their PICs at significantly lower costs. We have a
list of fifty companies, our user group, with potential
interest in this generic approach. The target is to increase
that to at least one hundred within two years.
DR: The strength of the EuroPIC approach is that
companies can get a handful of chips relatively cheaply
and quickly. If they end up wanting many wafers a year,
the same plants can produce that volume as well,
because all processes are carried out using industrial
facilities capable of high-volume production.
QWhy will SMEs have a better chance of success
by working with EuroPIC?
ADR: Any fabs would find it extremely difficult to work
with large numbers of SMEs. You really need some
kind of independent expertise in between the fabs and the
applications: people to organize the whole process;
people to do the design. The companies with the fabs do
not have the manpower available. However, it is true that if
a company was ramping its production to high volumes, it
would be worth its while to talk directly with a fab, but we
are talking about the companies starting in low volume.
The photonics industry has thinned down a lot since the
dot.com boom-and-bust at the turn of the century, and
very few of the big players who are left have the spare
capacity to take on this work.
QWill the EuroPIC foundries help companies to
speed products to market?
ADR: Yes. You can imagine a small SME with half a
dozen people trying to sort everything out for
themselves and struggling to get anywhere. When you
have this infrastructure available, rapid prototyping
becomes a reality. You will be able to go from an idea to
having a chip in your hands in a few months. It will be
incredibly different to the position we have now.
Q Do you think that Europe lags the US and Asia,
in terms of PIC development and
commercialization?
AMS: Europe had the lead in photonic integration in
the 1990s. However, after the turn of the century US
companies, such as Infinera, came up very rapidly.
However, in this novel approach - the generic technology -
Europe has a lead. Something like this is not happening in
the US or Japan. To succeed you need two things: a
34 www.compoundsemiconductor.net October 2010
interview � EuroPIC
consortium that is very closely co-operating, which we
have in Europe; and substantial supporting funding.
QWhere does the European foundry stand today?
ADR: It’s at an R&D level. The University of Eindhoven
is supporting the JePPIX operation, which runs an
R&D generic line on its open facility.
What we are trying to do is to move that understanding
and capability out into industry, where you can get all the
good things like volume, reliability, throughput. To do this,
EuroPIC is working with Oclaro in the UK and HHI
(Heinrich Hertz Institute) in Berlin. Philips is also playing a
role, although it is a little bit behind those to two foundries.
Although Oclaro’s technology is not advertised as large-
scale photonic integrated circuits in quite the way
Infinera’s technology is, it is every bit the equal of it. It
can do very similar things, but Oclaro has chosen until
now to apply it specifically to tunable lasers, modulators,
and so on.
QWhat are the benefits for Oclaro and HHI, the
key foundries in the EuroPIC project?
ADR: They are both fabs with a telecom base with a
huge amount of highly sophisticated technology
firmly directed in one narrow application area. They would
both like to see their technological abilities more broadly
deployed.
Q Tell me about the progress of EuroPIC?
ADR: It started on 1st August last year, and it’s a
relatively long cycle time to get the first generic line
set up. We have spent a year putting existing and new
pieces together in the process phase, and we are just
about to start our first runs at the InP processing facilities.
EuroPIC will aim to go through this cycle twice, in order
to iron out difficulties.
MS: What has been achieved now is mainly coming from
the JePPIX platform. This is research, but within two to
three years we hope to bring this to an industrial level. We
have selected ten different applications [see box “PIC
applications” for details], and they will all be put on the
two foundry lines. By the middle of next year we should
have one set of wafers from each of the foundries, each
wafer having a lot of quite different chips integrated on it.
Q Are the foundries continuing to refine their
technology?
ADR: Very much so. Although to be honest, EuroPIC
is a very broad, SME-based program, and there’s
not that much space for developing a radically new
semiconductor technology. The novelty in the program is
largely to do with putting end-to-end process together,
but there will be new technologies in packaging and
software.
However, the platform is capable of considerable
development in terms of the semiconductor technology
that goes into it, because there are a lot of different InP
alloys that you can use. There is the whole area of
quantum dots and nanotechnology, which we could go
into in the future.
QWhat wavelengths will these PICs operate at?
AMS: Initially the telecom C-band (around 1550 nm),
but the platform is capable of extension.
Q Are there facilities to package these chips?
ADR: Our packaging effort is rather small. There is a
resource limitation – EuroPIC is a € 6 million
program. We have one partner who is beginning to look at
the prospects of a generic packaging technology, CIP
Technologies in the UK. We are also starting new programs,
where packaging is a very large part of the activity.
MS: Our process is standardized on the interface
electrically and optically, so that you can use the same
package for a lot of different chips.
We can see that the chip price may go down by a factor
of more than ten. If the cost of packaging is not to
become the bottleneck, it will have to go down too, which
basically means cutting the cost of alignment using
leading edge packaging technologies; ‘clip-it-together’
and ‘plug-and-play’ techniques.
“We can see that the chip price may go down
by a factor of more than ten. If the cost of
packaging is not to become the bottleneck, it
will have to go down too, which basically
means cutting the cost of alignment using
leading edge packaging technologies; ‘clip-it-
together’ and ‘plug-and-play’ techniques.”
Meint Smit, Technical University of Eindhoven
October 2010 www.compoundsemiconductor.net 35
EuroPIC � interview
Q Do companies need to be worried about
compromising IP if they work with EuroPIC?
ADR: We have drawn up non-disclosure agreement
so we can work with our user group.
In the future we may have a brokering organization sitting
between the application and the InP fab. Contracts
between the broker and the fab, and the broker and the
application holders can sew up IP in a completely
watertight fashion.
Q How will SMEs work with the European PIC
foundry to develop products and bring them to
market?
AMS: If they have sufficient expertise in-house they
can design their mask set. But we expect that most
companies will not have that expertise, so we are also
working on the creation of design houses to generate
designs, just as you have design houses in
microelectronics.
Q How is the foundry funded at the moment?
AMS: Essentially European and national funding, with
some matching funding from industry, depending on
the scheme. The COBRA research school at TU/e is
underwriting JePPIX next year. COBRA runs training
courses based in the university’s electrical engineering
department on the design of the overall technology, and it
occasionally offers multi-project wafer runs.
In the Netherlands we have the so-called Memphis
(Merging Electronics and Micro & Nano-Photonics for
Integrated Circuits) Smart Mix project. It’s a big and rather
broad program, but there is substantial funding for this
generic approach.
There is another program in the Netherlands: the STW
Perpectief program GTIP, worth € 5.5 million, which is
fully devoted to generic integration technologies. It will
start at the end of this year.
DR: There is also PARADIGM (Photonic Adavanced
Manufacturing Platform for Photonic Integrated Circuits),
another EU project under negotiation, which will hopefully
start in the early autumn. It can be viewed as a successor
to EuroPIC. Paradigm will focus on technology developments,
such as packaging and InP processing technologies.
Assuming that Paradigm is funded, we will then have
€ 20-30 million going into this area, spread over about
twenty five different companies. This gives you a critical
mass to make you feel that you can make a central
European InP foundry a reality.
Q Given all the talk about austerity measures by
the governments of many European countries,
are you concerned over future funding of EuroPIC?
AMS: This technology will make product development
much cheaper, which must be a good message in
the current climate. For the coming two-to-three years
foundry based R&D will be in a good position with
secured funding. The critical point is this: will the
commercial market for low-cost PICs grow fast enough?
DR: I would add that these austerity measures by the
European governments are not over everything.
Governments are trying to cut their government
expenditure and stimulate their industries, and we are one
of the industries that can stimulate growth.
EuroPIC is aiming to assist the development of devices based on PICs that
can be deployed in a wide range of applications including:
� Telecom access networks, where they can be used in offices to integrate
many circuits, eliminating repetition for each subscriber or group of
subscribers.
� 10 Gbit/s access networks, where they could become competitive in the
subscriber transceiver module.
� Fiber-based sensors that monitor the integrity of large constructions,
such as bridges, dikes, roofs of large buildings and windmill propeller
blades. The cost of the sensor is dominated by that of the readout unit - a
light source, a detector and some signal processing circuitry – and a PIC
could replace a significant part of the existing module. According to the
Optoelectronics Industry Development Association, this market will be
worth more than $1 billion in 2011.
� Medical instruments, such as those based around the techniques of
Optical Coherence Tomography or Raman Scatterometry. PICs fabricated
from InP and its related alloys can operate at 1500 nm, a region of the
infrared spectrum where the penetration depth in skin is relatively high.
� High-speed pulse generators and clock recovery circuits; forms of ultrafast
analog-to-digital-converters; and multi-photon microscopy. All three applications
require lasers with very short pulse lengths, which can be produced with PICs
featuring mode-locked lasers, optionally combined with pulse shapers.
� Computer backplanes that use photonic interconnects to allow switching
in the optical domain. A EuroPIC fast photonic switch could serve terabit-
server backplanes, high-performance computing and multi-core architecture
connections.
� Radio-over-fiber systems providing wireless access.
PIC applications
To become a Corporate Partner and
be included in Compound Semiconductor
magazine Contact Tommy Beazley
T: + 44 (0) 1923 690 200
E: [email protected] Partnership
October 2010 www.compoundsemiconductor.net 37
review � research
Simplifying GaN VCSEL fabrication
THE process for making a room-
temperature GaN-based VCSEL capable of
continuous wave (CW) emission has been
simplified, thanks to efforts at National
Chiao-Tung University, Taiwan.
Corresponding author Tien-Chang Lu claims
that the group is this first to use an
AlN/GaN-based bottom DBR in this class
of device. “This is the first step toward the
all-epi type structure used in mature, GaAs-
based, 850 nm VCSELs.”
The breakthrough by Lu and his co-workers
could help to spur GaN VCSEL
commercialization. These devices have a far
lower threshold current than their edge-
emitting cousins, and could provide a more
efficient blue light source for Blu-ray pick-up
heads, portable micro-projectors, and high-
resolution laser mice.
Success at National Chiao-Tung University
follows Nichia’s report of the fabrication of
the first room-temperature, CW VCSEL in
2008. The Taiwanese researchers attribute
Nichia’s breakthrough to the introduction of
a thinner transparent conducting layer,
which cuts internal loss; and the growth of a
high-quality active region, thanks to
deposition on a GaN substrate.
Nichia’s approach to VCSEL fabrication is
complex, and involves laser lift-off and
elaborate polishing and bonding processes.
A far simpler approach is to grow a nitride-
based DBR and an active region on
sapphire by MOCVD, before adding a
dielectric DBR with an electron gun.
The Taiwanese researchers have pioneered
such a process, which begins with the
growth of a GaN buffer layer; a 29-pair
AlN/GaN DBR; a GaN/InGaN active region
featuring ten, 2.5 nm-thick quantum wells;
an electron-blocking layer; a 110 nm-thick p-
GaN layer; and a 2 nm-thick GaN-cap.
AlN/GaN superlattices were inserted into
the DBR to prevent cracking.
A 10 nm diameter aperture was defined by
deposition and selective removal of SiN. The
team deposited a current spreading layer
and n- and p-contacts on this, and then
added a ten-period Ta2O5/SiO2 DBR to
complete device fabrication.
Lu claims that this is the first GaN VCSEL
to feature an AlGaN electron-blocking layer.
This resulted in a relatively low threshold
current density of 9.7 mA, corresponding to
a threshold current density of 12.4 kA/cm2.
Turn-on voltage for the 412 nm laser was
Nichia’s LEDs hit new highsNichia has increased the efficacy of its LEDs that are being
developed for solid-state lighting.
Results from this Japanese optoelectronic device manufacturer
include a LED chip that delivers 1913 lumens at 135 lm/W when
driven at 1A. This chip combines four, 450 μm by 450 μm die in
series. According to the researchers, this LED has a higher flux
than a 20W-class fluorescent lamp and an efficacy 50 percent
higher than a tri-phosphor fluorescent lamp.
Nichia’s engineers have also fabricated a 1 mm by 1 mm chip that
produces 183 lm/W at 350 mA and 130 lm/W at 1A.
This set of results is broadly comparable to Cree’s recent
announcements. Nichia’s record for efficacy at 350 mA is not as
high as its US rival, which announced a 208 lm/W LED at 350 mA.
However, the dimensions of the more efficient device are unknown.
Cree has also unveiled a single chip device, the Xlamp XM LED,
which produces 110 lm/W at 2A and is slated for release this Fall.
Nichia’s recent success has stemmed from reducing the operating
voltage of its LEDs from 3.1 V to 2.8 V. Improvements in epitaxial
wafer quality and the introduction of ‘current-expanding’ electrodes
have help to cut operating voltage.
Y. Narukawa et al. J. Phys. D. Appl. Phys. 43 354002 (2010)
VCSEL growth involves MOCVD
deposition of a GaN-based epitaxial
stack, followed by ion-assisted electron
gun deposition of a Ta2O5/SiO2 DBR
4.3 V, output power peaked at just over
35 μW, and beam divergence was 8o.
The team’s next goal is to improve laser
beam quality. Lu says that this will be
accomplished through further reduction of
the threshold current, plus the addition of an
optical confining structure.
T.-C. Lu et al Appl. Phys. Lett. 97 071114
(2010)
38 www.compoundsemiconductor.net October 2010
research � review
Trapezoidal wells combat LED droopWIDER WELLS, slimmer barriers and
polarization-matched active regions have all
been used over the past few years to
minimize droop, the decline in LED
efficiency at higher drive currents. Inserting
trapezoidal wells into the active region can
now be added to this growing list, thanks to
the efforts of a team of researchers from
Korea.
These scientists from Gwangju Institute of
Science and Technology and Samsung LED
company claim that the addition of
trapezoidal wells increases electron-hole
overlap, which in turn cuts droop.
Two of the hallmarks of the Korean LED are
a slight reduction in forward voltage and
series resistance. Seong-Ju Park from
Gwangju Institute of Science and
Technology claims that these attributes stem
from superior carrier transport, which is the
result of a graded indium-composition in the
trapezoid well layer. The Korean team
compared the performance of their blue-
emitting trapezoidal LED with a conventional
equivalent. They made both of the devices
by depositing a GaN-based epitaxial stack
on sapphire by MOCVD, and then etching
550 μm by 550 μm mesas with an
inductively coupled plasma. Deposition of
ITO added transparent contacts.
Trapezoidal wells had a 0.5 nm-thick InGaN
core sandwiched between two 1.5 nm-thick
layers that were linearly graded in alloy
composition to 7.5 nm-thick GaN barriers.
Identical barriers featured in the
conventional LED, which had a 2.5 nm-thick
InGaN well. External quantum efficiency
(EQE) measurements revealed that the
trapezoidal LED produces a 19 percent
higher output at 35 A cm-2, rising to a 20
percent improvement at 70 A cm-2.
The EQE of the novel LED overtook the
control LED at 5 A cm-2. This is a very low
value compared with the crossover current
densities reported in previous studies by
other groups, according to the team. Both
of the devices were devoid of any light
extraction technology. This accounts for the
low values of EQE, which peaked at about
30 percent.
Modeling both device architectures with
LED simulator SiLENSe uncovered a
relationship between electron-hole overlap
and droop. Switching from the conventional
well to the trapezoidal one smoothed
conduction and valence bands profiles,
increased electron overlap from 37.2
percent to 41.6 percent, and cut the
distance between the maxima of the
electron and hole wavefunctions from
1.5 mm to 1.1 mm.
“Since the volume of the trapezoidal well is
20 percent smaller than the standard well,
our study shows that overlap of the
electron-hole wavefunction in the trapezoidal
well is more important than the non-radiative
Auger process,” claims Park.
Interestingly, Park can account for the
improved EQE of the double heterostructure
LEDs, which have been pioneered by
Lumileds as an approach for cutting droop.
He says that in this wide-well LED there is
very little band-bending of the InGaN layer.
“This result indicates that the electron-hole
wavefunction overlap in the double
heterostructure can be much higher than in
the quantum well.”
S.-H. Han et al. J. Phys. D. Appl. Phys. 43
354004 (2010)
HRL speeds E-mode transistor
HRL Laboratories claims to have
simultaneously broken three records for an
enhancement-mode, GaN HFET: maximum
transconductance; highest cut-off
frequency; and the highest value for
maximum oscillation frequency.
The AlN/GaN/AlGaN double heterojunction
FET developed by HRL had a peak
transconductance of 700 mS/mm, a cut-off
frequency of 112 GHz and maximum
oscillation frequency of 215 GHz.
Although these values are inferior to best
figures produced by their far more common
depletion-mode cousins, the E-mode version
has one major advantage: it is normally off.
This simplifies circuit design; aids power
switching, by reducing power consumption
and increasing safety; and enables creation
of E/D-mode logic for digital circuits and
mixed-signal applications.
HRL’s motivation for its efforts is focused on
the development of GaN transistors and
integrated circuit technology for high-
performance analog-to-digital converters
that can be deployed in future advanced
electronic systems. This work is funded by
DARPA’s NEXT program.
The engineers at HRL attribute their
success to aggressive reduction of parasitic
resistances and vertical scaling.
Fabrication of the double-heterostructure
FETs involved the growth of a GaN-based
epitaxial stack on 3-inch SiC. This comprised
an Al0.08Ga0.92N buffer, a 20-40 nm GaN
channel, a 2 nm AlN barrier and a 2.5 nm cap.
Mesas were formed in the material, before
plasma-enhanced CVD deposited a SiO2
mask. This was patterned and etched to
within 20 nm of the sample surface in the
source and drain regions. MBE growth of a
50 nm, heavily silicon-doped GaN layer was
added to facilitate the formation of low-
resistance ohmic contacts, before the
silicon mask was removed.
After Ti/Al/Pt contacts were deposited, T-
shaped Pt/Au gates were added by:
depositing a sacrificial mask layer;
patterning the gate foot with e-beam
lithography; and performing gate top
lithography, metallization, liftoff and mask
removal.
These record-breaking E-mode double
heterostructure FETs had a 2 x 37.5 μm
gate periphery and produced a maximum
drain current of 0.92 mA/mm at 2 V gate
bias. On-resistance was 1.06 Ω mm.
Cut-off frequency and maximum oscillation
frequency records were realized at a drain
bias of 2.0 V. According to HRL’s engineers,
previous claims for these records have
tended to employ higher drain biases,
typically 5-10 V, which were needed to
overcome the excess voltage drop across
parasitic resistances.
The team claims that optimized lateral-device
scaling could spur further improvements in
its E-mode FET performance.
A. Corrion et al. to appear in Electron. Dev.
Lett. (2010)
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